Infiniti EX35. Manual - part 669

EC-418

< COMPONENT DIAGNOSIS >

[VQ35HR]

P1805 BRAKE SWITCH

P1805 BRAKE SWITCH

Description

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Brake switch signal is applied to the ECM through the stop lamp switch when the brake pedal is depressed.
This signal is used mainly to decrease the engine speed when the vehicle is driving.

DTC Logic

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DTC DETECTION LOGIC

DTC CONFIRMATION PROCEDURE

1.

PERFORM DTC CONFIRMATION PROCEDURE

1.

Turn ignition switch ON.

2.

Fully depress the brake pedal for at least 5 seconds.

3.

Erase the DTC.

4.

Check 1st trip DTC.

Is 1st trip DTC detected?

YES

>> Go to 

EC-418, "Diagnosis Procedure"

.

NO

>> INSPECTION END

Diagnosis Procedure

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1.

CHECK STOP LAMP SWITCH CIRCUIT

1.

Turn ignition switch OFF.

2.

Check the stop lamp when depressing and releasing the brake pedal.

Is the inspection result normal?

YES

>> GO TO 4.

NO

>> GO TO 2.

2.

CHECK STOP LAMP SWITCH POWER SUPPLY CIRCUIT

1.

Disconnect stop lamp switch harness connector.

2.

Check the voltage between stop lamp switch harness connector and ground.

Is the inspection result normal?

YES

>> GO TO 4.

NO

>> GO TO 3.

3.

DETECT MALFUNCTIONING PART

Check the following.
• Fuse block (J/B) connector E103
• 10A fuse (No. 7)

DTC No.

Trouble diagnosis name

DTC detecting condition

Possible cause

P1805

Brake switch

A brake switch signal is not sent to ECM for ex-
tremely long time while the vehicle is driving.

• Harness or connectors

(Stop lamp switch circuit is open or short-
ed.)

• Stop lamp switch

Brake pedal

Stop lamp

Fully released

Not illuminated

Slightly depressed

Illuminated

Stop lamp switch

Ground

Voltage

Connector

Terminal

E110

3

Ground

Battery voltage

P1805 BRAKE SWITCH

EC-419

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• Harness for open or short between stop lamp switch and battery

>> Repair open circuit or short to ground or short to power in harness or connectors.

4.

CHECK STOP LAMP SWITCH INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT

1.

Disconnect stop lamp switch harness connector.

2.

Disconnect ECM harness connector.

3.

Check the continuity between stop lamp switch harness connector and ECM harness connector.

4.

Also check harness for short to ground and short to power.

Is the inspection result normal?

YES

>> GO TO 6.

NO

>> GO TO 5.

5.

DETECT MALFUNCTIONING PART

Check the following.
• Fuse block (J/B) connector E103, M2
• Harness for open or short between ECM and stop lamp switch

>> Repair open circuit or short to ground or short to power in harness or connectors.

6.

CHECK STOP LAMP SWITCH 

Refer to 

EC-419, "Component Inspection (Stop Lamp Switch)"

.

Is the inspection result normal?

YES

>> GO TO 7.

NO

>> Replace stop lamp switch.

7.

CHECK INTERMITTENT INCIDENT

Refer to 

GI-38, "Intermittent Incident"

.

>> INSPECTION END

Component Inspection (Stop Lamp Switch)

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1.

CHECK STOP LAMP SWITCH-I

1.

Turn ignition switch OFF.

2.

Disconnect stop lamp switch harness connector.

3.

Check the continuity between stop lamp switch terminals under the following conditions.

Is the inspection result normal?

YES

>> INSPECTION END

NO

>> GO TO 2.

2.

CHECK STOP LAMP SWITCH-II

1.

Adjust stop lamp switch installation. Refer to 

BR-7, "Inspection and Adjustment"

.

2.

Check the continuity between stop lamp switch terminals under the following conditions.

Stop lamp switch

ECM

Continuity

Connector

Terminal

Connector

Terminal

E110

4

M107

122

Existed

Terminals

Condition

Continuity

3 and 4

Brake pedal

Fully released

Not existed

Slightly depressed

Existed

EC-420

< COMPONENT DIAGNOSIS >

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P1805 BRAKE SWITCH

Is the inspection result normal?

YES

>> INSPECTION END

NO

>> Replace stop lamp switch.

Terminals

Condition

Continuity

3 and 4

Brake pedal

Fully released

Not existed

Slightly depressed

Existed

P2122, P2123 APP SENSOR

EC-421

< COMPONENT DIAGNOSIS >

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P2122, P2123 APP SENSOR

Description

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The accelerator pedal position sensor is installed on the upper end
of the accelerator pedal assembly. The sensor detects the accelera-
tor position and sends a signal to the ECM.
Accelerator pedal position sensor has two sensors. These sensors
are a kind of potentiometers which transform the accelerator pedal
position into output voltage, and emit the voltage signal to the ECM.
In addition, these sensors detect the opening and closing speed of
the accelerator pedal and feed the voltage signals to the ECM. The
ECM judges the current opening angle of the accelerator pedal from
these signals and controls the throttle control motor based on these
signals.
Idle position of the accelerator pedal is determined by the ECM
receiving the signal from the accelerator pedal position sensor. The ECM uses this signal for the engine oper-
ation such as fuel cut.

DTC Logic

INFOID:0000000003133600

DTC DETECTION LOGIC

NOTE:
If DTC P2122 or P2123 is displayed with DTC P0643, first perform the trouble diagnosis for DTC P0643.
Refer to 

EC-339, "DTC Logic"

.

DTC CONFIRMATION PROCEDURE

1.

PRECONDITIONING

If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
TESTING CONDITION:
Before performing the following procedure, confirm that battery voltage is more than 10 V at idle.

>> GO TO 2.

2.

PERFORM DTC CONFIRMATION PROCEDURE

1.

Start engine and let it idle for 1 second.

2.

Check DTC.

Is DTC detected?

YES

>> Go to 

EC-421, "Diagnosis Procedure"

.

NO

>> INSPECTION END

Diagnosis Procedure

INFOID:0000000003133601

1.

CHECK GROUND CONNECTION

1.

Turn ignition switch OFF.

2.

Check ground connection M95. Refer to Ground Inspection in 

GI-41, "Circuit Inspection"

.

Is the inspection result normal?

YES

>> GO TO 2.

PBIB1741E

DTC No.

Trouble diagnosis name

DTC detecting condition

Possible cause

P2122

Accelerator pedal posi-
tion sensor 1 circuit low 
input

An excessively low voltage from the APP sen-
sor 1 is sent to ECM.

• Harness or connectors

(APP sensor 1 circuit is open or shorted.)

• Accelerator pedal position sensor

(APP sensor 1)

P2123

Accelerator pedal posi-
tion sensor 1 circuit high 
input

An excessively high voltage from the APP sen-
sor 1 is sent to ECM.